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Finally took my '66 Black Bomber for a ride! First impressions...

Laverdista

Member
Joined
Sep 12, 2022
Total Posts
27
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0
Location
Malvern, UK
So... after a two-week delay since I got it home, brought about by a combination of terrible weather and a nasty bout of Covid, I finally took my newly-acquired Black Bomber for a 30 mile ride.

All OK (but see below) and overall, I enjoyed it! Below are some random thoughts/observations (in no particular order!):


Took me a few minutes to get used to the gearchange on the 'wrong side' (all my other bikes are right foot gearchange) but otherwise OK.

I was delayed in getting out the door, as for some reason the main fuse (glass fuse by battery) had blown. Have absolutely no why - Unless I had accidentally shorted something when fishing around in the headlight (had a quick look, as am going to fit an LED headlamp bulb). It had certainly been OK when I left it a couple of days ago. Anyway, unfortunately I didn't have any glass fuses to hand, so in order to get out the door I've temporarily swapped it for a blade fuseholder and fuse, which does at least have the advantage of being easy to replace should it blow again. :)

Really impressed with the brakes, although found the handling 'satisfactory' rather than 'great'. I think I might replace the tyres next Spring, as they look to be about 15 years old! I also wonder about putting the original shocks in a box for a future owner (nice as they look, and I know previous owner Chris Saxby spent a good while rebuilding them), and fitting a pair of Hagons instead, but I'm going to hang on for now until I get to know the bike better.

Although it wouldn't idle initially, it idled satisfactorily after my run, although I have tweaked it a tiny bit.

It sounds absolutely lovely, and picks up really well, although I don't feel ready to test the rev limit yet. My Laverda red lines at about 6k, so getting used to a bike with a red line at 9.5k will take some time.

Performance seems strong for a 450! I'm running B7ES's (as that was what was in there before, and I had some 'on the shelf', but will check the tip colour, and if necessary change to B8ES's.


The only downside at the moment is the clutch, which is horrible. It seems to be slipping, and I have very little clutch travel. I'll change down to first at a junction, and when I let the clutch out nothing seems to happen until near the top of the lever travel. I'm hoping it's not a case of new clutch, maybe just an adjustment issue.

And if I slow down for a junction (not stopping completely) and then go from first to second too early, it's not liking it - Getting a 'clunk' from the cush drive? Anyway, I think I'll look to sort the clutch out first and take it from there. It's a shame, because otherwise the bike feels really strong - No rattles, clonks or unwelcome noises. Chris had obviously done a nice job setting up the engine all those years ago.

bbtuesday.jpg

Cheers,

James
 
The clutch behavior sounds like it needs a tad more free play at the lever, it might not have enough slack to allow full, crisp engagement. As for the clunk between first and second, there is no cush drive - at least, not like some of the other Hondas with rubber dampers in the hub and "vanes" on the sprocket drive flange that sit in between them, your rear sprocket has stud-bolts that sit in small cylindrical inserts in the hub that have metal tubes bonded into reasonably hard rubber so you'll feel and hear virtually nothing from that area. There's no cush of any sort in the transmission internals either. There is a wide ratio gap between first and second as most of the 4 speeds had back then, and the more significant difference in transmission rpm between the two gears can cause more of a clunk when the revs aren't up higher. If you haven't yet changed the oil, I would unless you know specifically how many miles are on it and how long it sat in between Chris' ownership and yours. I'm sure you're aware after talking to Chris that this engine is more dependent on good clean oil circulation for the proper survival of the cams and followers, particularly the exhaust cam which is last in oil flow reception, and good low rpm warmups are a necessity to allow oil flow to reach them before riding off or you'll cause premature wear on the cam lobes and followers. Give it a full 1 to 2 minutes at the lowest rpm it will run when starting it up cold. Also, older engines often don't idle well cold, one of the reasons Honda suggests adjusting idle mixture and speed once fully warmed up.

It sure is a beauty.
 
Thanks, that's really good to know. I did change the oil (as good practice) before I used it. Either way, the previous owner had used 10w30 oil in it, which seems a bit thin? Point taken about the warming up procedure, and I'm going to be a bit anally retentive about it going forwards! I'm off to the Auto Moto d'Epoca show in Padua in a couple of weeks (I haven't been for 20 years, and treating my 16-year old son to a visit there combined with a day in Venice) so thinking I might look out for a good price (If such a thing exists!) on a Capellini oil pump in the spare parts hall while I'm there!

I think (hope!) it's just a clutch adjustment issue. I did back the lever adjuster off a little bit (it now has about 25% of its travel before engaging) and greased the nipple on the actuator casing. It does seem to be moving properly (from what I can hear) so we'll see what its like on the next run. If the worst comes to the worst I will back everything off (including the adjuster on the casing) and go through it methodically. Hopefully there's still a bit of life left in the clutch yet!

Interesting about the lack of cush drive. OK, I think that any driveline shunt must be down to the clutch adjustment, plus I'll give the chain a good lube as well.

Thanks for the feedback/tips. It's all still at the 'totally alien' stage for me, despite having a lot of experience with Italian bikes! :)

The clutch behavior sounds like it needs a tad more free play at the lever, it might not have enough slack to allow full, crisp engagement. As for the clunk between first and second, there is no cush drive - at least, not like some of the other Hondas with rubber dampers in the hub and "vanes" on the sprocket drive flange that sit in between them, your rear sprocket has stud-bolts that sit in small cylindrical inserts in the hub that have metal tubes bonded into reasonably hard rubber so you'll feel and hear virtually nothing from that area. There's no cush of any sort in the transmission internals either. There is a wide ratio gap between first and second as most of the 4 speeds had back then, and the more significant difference in transmission rpm between the two gears can cause more of a clunk when the revs aren't up higher. If you haven't yet changed the oil, I would unless you know specifically how many miles are on it and how long it sat in between Chris' ownership and yours. I'm sure you're aware after talking to Chris that this engine is more dependent on good clean oil circulation for the proper survival of the cams and followers, particularly the exhaust cam which is last in oil flow reception, and good low rpm warmups are a necessity to allow oil flow to reach them before riding off or you'll cause premature wear on the cam lobes and followers. Give it a full 1 to 2 minutes at the lowest rpm it will run when starting it up cold. Also, older engines often don't idle well cold, one of the reasons Honda suggests adjusting idle mixture and speed once fully warmed up.

It sure is a beauty.
 
Thanks, that's really good to know. I did change the oil (as good practice) before I used it. Either way, the previous owner had used 10w30 oil in it, which seems a bit thin? Point taken about the warming up procedure, and I'm going to be a bit anally retentive about it going forwards! I'm off to the Auto Moto d'Epoca show in Padua in a couple of weeks (I haven't been for 20 years, and treating my 16-year old son to a visit there combined with a day in Venice) so thinking I might look out for a good price (If such a thing exists!) on a Capellini oil pump in the spare parts hall while I'm there!

I think (hope!) it's just a clutch adjustment issue. I did back the lever adjuster off a little bit (it now has about 25% of its travel before engaging) and greased the nipple on the actuator casing. It does seem to be moving properly (from what I can hear) so we'll see what its like on the next run. If the worst comes to the worst I will back everything off (including the adjuster on the casing) and go through it methodically. Hopefully there's still a bit of life left in the clutch yet!

Interesting about the lack of cush drive. OK, I think that any driveline shunt must be down to the clutch adjustment, plus I'll give the chain a good lube as well.

Thanks for the feedback/tips. It's all still at the 'totally alien' stage for me, despite having a lot of experience with Italian bikes! :)

If the clutch is truly worn it will slip in the higher gears under heavy load, otherwise you should be able to adjust the free play at the lever to achieve proper engagement. Since the cables usually stretch a bit as the engine heat affects them, you'll want a a smaller amount of free lever movement when cold but not tight to the perch either. I typically keep the lever movement to about 1/8" to 3/16" (about 3mm to 5mm) when cold as mine expands to roughly twice that when hot, but cables and their reactions to heat vary.

Don't spend the money and engine disassembly time (yes, serious internal modifications are required) for the Cappellini pump. Get the modern replacement gear pump designed and sold by our own VHT member Jays100 that bolts right into the factory location and requires only one small mod to the right crankcase (clutch) cover, it has over double the output and flow as the factory pump and gets oil to the top end over twice as fast. Many members are using them, and it's less than half the cost of Cappellini's pump even before the required engine modifications to install theirs.
 
If the clutch is truly worn it will slip in the higher gears under heavy load, otherwise you should be able to adjust the free play at the lever to achieve proper engagement. Since the cables usually stretch a bit as the engine heat affects them, you'll want a a smaller amount of free lever movement when cold but not tight to the perch either. I typically keep the lever movement to about 1/8" to 3/16" (about 3mm to 5mm) when cold as mine expands to roughly twice that when hot, but cables and their reactions to heat vary.

Don't spend the money and engine disassembly time (yes, serious internal modifications are required) for the Cappellini pump. Get the modern replacement gear pump designed and sold by our own VHT member Jays100 that bolts right into the factory location and requires only one small mod to the right crankcase (clutch) cover, it has over double the output and flow as the factory pump and gets oil to the top end over twice as fast. Many members are using them, and it's less than half the cost of Cappellini's pump even before the required engine modifications to install theirs.
Thanks for that info.

Ref. The clutch lever free play, are you talking about at the tip of the lever, or at the perch?

Thanks for the intro to Jay as well. I had actually looked at the thread about his oil pump but couldn't see anything about ordering details. I'll message him. I nearly fainted when I sw the price of the Capellini pump, plus I didn't realise the amount of machining required. Jay's sounds like a much better solution.

James
 
Thanks for that info.

Ref. The clutch lever free play, are you talking about at the tip of the lever, or at the perch?

Thanks for the intro to Jay as well. I had actually looked at the thread about his oil pump but couldn't see anything about ordering details. I'll message him. I nearly fainted when I sw the price of the Capellini pump, plus I didn't realise the amount of machining required. Jay's sounds like a much better solution.

James

Yes, the gap between lever and perch is the measurement I mentioned, has always worked for me. To do the adjustment properly, you should loosen all of the cable slack at the bottom of the cable (screwed all the way in) and leave yourself a couple turns of (looser) adjustment at the lever end of the cable, then use the clutch throwout mechanism adjuster on the front sprocket cover for the large portion of adjustment, turning the large flat screwdriver slotted adjuster (use a large coin like a US quarter) to take all but the last little bit of adjustment necessary turning to the right, then use the upper and/or lower cable adjustments for the fine tuning.

The Cappellini pump is basically an Eaton industrial pump with a lot of pressure (~60 lbs) but is chain driven and requires a lot of modifications to the engine to properly employ. Jay's pump is as simple and as good as it gets, especially for the price.
 
Yes, the gap between lever and perch is the measurement I mentioned, has always worked for me. To do the adjustment properly, you should loosen all of the cable slack at the bottom of the cable (screwed all the way in) and leave yourself a couple turns of (looser) adjustment at the lever end of the cable, then use the clutch throwout mechanism adjuster on the front sprocket cover for the large portion of adjustment, turning the large flat screwdriver slotted adjuster (use a large coin like a US quarter) to take all but the last little bit of adjustment necessary turning to the right, then use the upper and/or lower cable adjustments for the fine tuning.

The Cappellini pump is basically an Eaton industrial pump with a lot of pressure (~60 lbs) but is chain driven and requires a lot of modifications to the engine to properly employ. Jay's pump is as simple and as good as it gets, especially for the price.
Thank you. Did a full 'reset' on the clutch adjustment (both cable adjusters wound in, the 'coin slot' adjuster in the casing turned clockwise until it makes contact, then backed off a tiny bit, and slack taken up at casing, then lever), and it seems a lot better now. Going to take it for a spin tomorrow to confirm. Have also lubed and cleaned the chain - It needed it! [emoji2]

Cheers,

James
 
Thank you. Did a full 'reset' on the clutch adjustment (both cable adjusters wound in, the 'coin slot' adjuster in the casing turned clockwise until it makes contact, then backed off a tiny bit, and slack taken up at casing, then lever), and it seems a lot better now. Going to take it for a spin tomorrow to confirm. Have also lubed and cleaned the chain - It needed it! [emoji2]

Cheers,

James

Good deal, let us know how it behaves.
 
So...

Took it out for a spin yesterday. I'd obviously not adjusted the clutch properly, as it didn't want to release cleanly, and I couldn't change gear, plus when I did get it going it started to slip at high revs.

Wound in the adjuster on the lever a bit more (to probably 7mm slack at the perch) and got it to stop slipping, plus I had a gearchange that worked again.

My gut feeling is that it might still benefit from some new clutch plates and springs, possibly a new cable too, but it could also be my inexperience with these clutches, so I'll take it for some more runs and see how it goes.

Do any non-racers uprate their clutch springs? I have to admit, I'm used to the clutch on my Laverda (after years of using it, I can crush walnuts with my left hand [emoji2]), so the lightness of the Honda clutch is unsettling!

Also, I must admit that I don't find the gear change very 'positive' -I'm used to a proper click when changing gear on most of my other bikes, but this is 'softer', more a bit of pressure from my left foot and I've changed gear. It could all be down to clutch adjustment/wear.

Otherwise, the bike feels 'spot on' - Great brakes, engine pulls really well, and I'm getting used to the handling, although I'm definitely going to fit Hagons, and it will get a new set of K82s for next year (I toyed with fitting some Avon RoadRiders in 90/90 and 100/90, but I think they'll ruin the period look of the bike, even if I do love their grip).

Clutch notwithstanding, I think this bike will be a 'keeper'. [emoji2]
 
Check your outer clutch mechanism, take a good look at the worm gear which pushes the clutch shaft. Check your clutch shaft for bending. Next, take the (engine)side cover off (after dropping the oil), check the plates, and clutch basket. And since you're in there, check your shift mechanism for wear.

A CB450K0 will never shift like a modern bike, but can do much better then you describe. The clutch should be perfect, the six spring does it's job well, no need the use heavier. But check your springs for specifications. The K0 is using the best clutch of all 450's, and is often used in later engines (originally a 4-spring). On high miles bikes the clutch basket can be damaged beyond repair, but seldom seen by me.

If the oil you using has friction modifiers, it can be a problem too (slipping clutch).

Personally, I don't care about a classic look for tires, and use the BT45's, the best tire I can get for the K0 (at dry and wet roads). Hagons are fine, but don't forget the front fork springs, these are mostly way too soft after 60 years. And if working on the front forks, chancing the seals, oil and cleaning the internals won't harm the longevity of them.
 
Thanks for that. I think I'm just going to have to methodically work my way through the entire clutch mechanism.

I did notice that David Silver (I think?) sell a remanufactured worm gear/actuator. But I'll see what mine is like first.

I'm also going to change from the 10w30 oil that the current owner used (the oil and filter were clean, so I haven't changed it yet) to something a bit heavier. 10w40 maybe. Not sure if that is contributing to slipping, but I need to change it anyway.

I may talk to Maxton about uprating the front forks (they're not too far away from me anyway), but first I need to get that clutch working properly! [emoji2]

Thanks,

James
Check your outer clutch mechanism, take a good look at the worm gear which pushes the clutch shaft. Check your clutch shaft for bending. Next, take the (engine)side cover off (after dropping the oil), check the plates, and clutch basket. And since you're in there, check your shift mechanism for wear.

A CB450K0 will never shift like a modern bike, but can do much better then you describe. The clutch should be perfect, the six spring does it's job well, no need the use heavier. But check your springs for specifications. The K0 is using the best clutch of all 450's, and is often used in later engines (originally a 4-spring). On high miles bikes the clutch basket can be damaged beyond repair, but seldom seen by me.

If the oil you using has friction modifiers, it can be a problem too (slipping clutch).

Personally, I don't care about a classic look for tires, and use the BT45's, the best tire I can get for the K0 (at dry and wet roads). Hagons are fine, but don't forget the front fork springs, these are mostly way too soft after 60 years. And if working on the front forks, chancing the seals, oil and cleaning the internals won't harm the longevity of them.
 
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